Diffusion tensor imaging of the white matter in young adults aged 18-25 years with first-episode major depression disorder

Objective To investigate the microstructural alternations of the white matter nerve circuit detected by diffusion tensor imaging (DTI) in young adults aged 18-25 years with first-episode major depression disorder (MDD) and explore the association of such changes with the symptoms and disease course of depression. Methods From June to December, 2018, 23 young adults aged 18-25 years with the diagnosis of MDD were recruited from the Department of Medical Psychology of our hospital as the depression group, with 25 age-matched healthy volunteers as the control group. All the participants were tested using the Center for Epidemiological Studies Depression Scale (CDS-D) and the 9-item Patient Health Questionnaire (PHQ-9), and DTI images were obtained by magnetic resonance scanning and analyzed using tract-based spatial statistics (TBSS) method. Correction for multiple comparisons was carried out using a threshold-free cluster enhancement (TFCE) method. The differences in the fractional anisotropy (FA), radial diffusivity (RD), mean diffusion (MD) and axial diffusivity (AD) between the 2 groups were analyzed. The correlations of FA, RD, MD and AD values in the brain regions showing microstructural alternations with the PHQ-9 scores and the disease course were also analyzed. Results Compared with the healthy volunteers, the patients with first-episode MDD showed significantly decreased FA values in the left superior longitudinal tract, the right anterior thalamic radiation and the bilateral corticospinal tract (P < 0.05) and increased RD values in the left superior longitudinal tract (P < 0.05); the MD and AD values did not differ significantly between the two groups. In the patients with MDD, the RD values of the left superior longitudinal tract was positively correlated with the disease course (r=0.534, P < 0.05), and the FA values of the left corticospinal tract was negatively correlated with the disease course (r=-0.659, P < 0.05); The FA and RD values of the left superior longitudinal tract, the right anterior thalamic radiation and the bilateral corticospinal tract were not significantly correlated with the PHQ-9 scores (P>0.05). Conclusion The patients with MDD in their early adulthood have obvious alternations of the white matter fiber nerve circuit, which can be related with the disease course of MDD.